Method and means for raising and lowering portable derricks



METHOD AND MEANS FOR RISING AND LOWERING' PORTABLE DERRICKS Filed May 6, 1944 Y 2 Sheets-Sheet 1 l'snnentor HOWARD D. H/LoR/v.

July 2, 1946. H. D. HILBORN v 2,403,080 METHOD AND MEANS FOR* RAISINGVAND LOWERING PORTABLE 'DERRICKS Filed May 6l, 1944 "2 Sheets-Shleet 2 :S llll tot s liv Patented July 2v, 1946 METHOD AND MEANS FOR BAISING AND `L()Wl?.'l.l1\(r PORTABLE DERBICKS l Howard DQHilborn, Houston, Tex., assignor to Emsco Derrick a Equipment Company, Los Angeles, Calif., a corporation of ,Californian Appueationmay e. laisserai No. 534.419 5 claims. (ci. lss-15) My invention relates to portable derricks of the type employed for well drilling, and relates in particular to a method and means whereby the weight of the derrick is caused to .act to swing the derrick in one direction only during the time the derrick is moved between fully erect and reclining positions.

An object of the invention 1s to provide a method and means whereby the pivot point 'aroundvwhich the derrick swings when it is either raised from reclining position to erect position or lowered from erect position to reclining position is shifted from the front legs to the rear legs of the derrick as the center of gravity of the der- -rick passes over the lower extremities of the front legs, thereby making it possible to raise or lower the lderrick without the luse of a snubbing line during the time the derrick is being raised and the derrick will be then` supportedsubstantially entirely upon its front legs during the time it is swung further toward and intol reclining position.

l Itis alsoan object of the invention to provide a method4 and means whereby a derrickis lowered bylilrst changing the height relationship of the lower ends of the front less and real-"legs of the derrick so that the derrick will'be swung into an inclined position wherein the center of. gravity is substantially verticallyabove or slightlyffor.

wardly of the supporting'means for theffront derrick legs and the derrick is thereafter `swung into reclining position around thelowerf'endsof its front legs, thereby avoiding the necessityof first pulling the derrick into an oil center, position to bring it toa position wherein its weight without the necessity of pulling the derrick oil! cnter when starting to lower the derrick.

It is an object of the invention to provide means for vadjusting or shortening the supporting means of the front sido of the derrick so thatthe rear legs of the derrick will support substantially the entire derrick load during the time the center of gravity of the derrick is within `the vertical projection'of the base area deiined by the lower ends of thefour derrick legs, or, otherwise stat-- ed, during the timethe center of gravity ofthe derrick "is rearward of a position substantially 'vertically above the supporting means for the front le'gs ofthe derrick. f

A featureof my inv on is that during the operations of ,raising}' lowering the derrick, the 'weight of the derricky tends to swing the derrick in one directiononly', namely forwardly. By the expression adjusting in this disclosure I mean changing the position of one-or more of the supporting vmeans for the front legs, or removing part of the supporting means so that the supporting means at the front side of the will thereafter act yto move it downward to reclining position.

Further objects and advantages of .thefinven- ,A

tion will be brought out in the followingparteiof the speciilcation. i i f Referring' to the drawings whicharefvfor'illustrative purposes only, l v Fig.' 1 is a schematic elevationalview showiir a preferred embodiment of my invention'. Fls. 2 is a cross section taken as indicated'y thelineZ-Z ofFlg. 1.

support ofFig. 1. 2f v. -v

VF18'. 4 is a perspective viewshowinga'fr'ont Fis. 3 is a perspective showing'ra rear leg.

.'1 leg supportof Eig 1.

Fig. 5 is-` a perspective Viewl of an alternative front leg support which maybe used in the pracderrick will be in eifectremoved, and the load of 'the derrick will be then carried substantially en tirely by the rear legs of the derrick.

It is a'furthervobject of thevinvention to provide a method and means suchgasiset forth in the foregoing having front supportsffor the derrick which will permit downward movement of the front side of the derrickso that the derrick will be swung by its own weight in forward direction around the 'lower ends of the rear legs of the derrick to a position wherein the' center'of gravity of the derrick is substantially vertically above the supporting means for the front legs of the derrick or slightly forwardly thereof, whereupon Atice f my invention.

Fig. 6 is yiiiperspective form rerles support v In Fig. 1 I show the portable derriclgfiferct ,view Vof an `alternative on a base Ii` shown as beingsummd on a foundation member l2, and` carrying tits rear end engines I3 and a drawwoi-ks 'Il arr to be driven by the engines I3.

The dem has fear' has' is which' tra v t substantially half the derrlckload through the lower ends I6 ,thereofto rear'leg supports il, and the derrick has front legs ilv which carry the .reminder ofthe derrick'load through their lower ends Il to front leg supports 20 which iormparts of adjustable front leg supporting means of the invention. y Adjacent the rear legs I5 of the derrick I0 lthere is a gin pole structure 2i carrying a suitable number of sheaves 22yover which lines or cables 22'v and 23 maybe carried' for use in raising and lowering the derrick I Il. The ar- 55 rangement of lines or'sheaves forraising'and' ,erect position as shown in Fig. 1. `ferred form of the invention, the depression or `socket 24 is formed in the upper edges of plates invention, and it will be understood that any arrangement of cables -attached to the derrick so as to pull rearwardly thereon may be employed in the practice of the invention, the rearward pull of the cables serving either to raise the derswings under its own load from erect position to reclining position upon theground.

As shown in Fig. 3, each rear leg support I1 comprises a rest` or depression 24 in Iwhich the lower end I6 of the rear leg I5 may rest and in which it may be secured when the derrick is in which are spaced so that the lower extremity `of the rear leg I5 may be received therebetween, ,and a portion of the rear leg, which rests in the `depression or socket 24, comprises a pin 26 which `is extended horizontally through the lower end of the leg l5. For homing the pin` 2s in the depressions 24` of the plates 25, holddown yokes `21 are provided, one of these yokes 21 being `shown displaced laterally from its normal posi tion. f'Each yoke 21 is removably ,held by cap lowering the derrick.

Each front'leg support2ll, as yshown in Fig. 4.

l includes a pair of spaced plates 29 defining a space 4 l 30 toguide and receive the lower end of a front leg I8. Each of the plates 29 has therein a slot 3| which is substantially vertical, Abut preferably describes an arc around the axisvof the socket 24j i of the rear leg support I1 opposite thereto so that l as the derrick Il! swings from the erect position` I thereof shown in full lines in Fig. l to the interl mediate position indicated by dot and dash lines,

. a pin 33, carriedby the lower extremity of the frontleg I6 so thatl the ends thereof project y throughthe slots` 3| may vtravel downward in the l slots 3l from the raised position thereof shown in Figi 4.*

The upper ends., of the plates 23 haveA therein depressions or sockets 35 to receive the ends of a ,pin 36` adapted to be passed through an opening 31 irrth'e lower end I9 of the frontleg I8 when 3 the pin '33 occupies j ends offtlie a position near `the upper supporting'member 20. Tlii's'pv n 6 transmits vthe y letsel. The lower end-I9 of each g front'leg 'I8constitutesamember which is in conload of the cooperating front'lgl'to" the platesI` 29 when the fderrick is-in use in erectp'o'sition, and

yokes 'are provided to-superiorly'engage the';

` projecting endy portions' 4I `of ythe pin to lock the lowe'rends I9 of the legs to theplate's l29 which are secured to the lbase I I inany desired manner.v

'I'helutili'ty of my invention will'be perceived l from Athfefollowing .description of the manner of lowering and raising the derrick. If it is desired tolower'the derrick, a strain is placed on the lines l 22 andjj23 which will tend to swing the derrick leftward direction, thereby'relieving the` the pins 36 at the lower ends of the' l of inAFig.' 4, ,'It will be understood that the Ivertical weightloflthe derrick is now carried by 'the rearlegsl tfandthatthe weight would i swing the VderrickAl Ill in clockwise `direction on the legs l5 were it not for the restraining action of the lines 22 and 23.

The lines 22 and 23 are now gradually released or extended so that the vderrick Ill mayswing from the position 4in whichI it is shown in full lines toward the position indicated by dot and dash lines in Fig.` 1, during which time the pins 33 will travel downward in the slots'3I, the weight of the derrick Ill acting eccentrically with relation to the pins 26, producing this clockwise swinging move. ment of the derrick I0. The bottom walls 43 of the slots 3I are vso placed that they will be engaged by the ends of the pins 33 when the derrick I0 has swung through such distance as to bring its center of gravity G into a position G substantially vertically above a line drawn through the lower ends of the front legs I8 of the derrick, or substantially vertically above the pins 33 so` that there will be no difficulty in producing a continued forward or downward movement of the derrick from the position' shown in dot and dash lines to the reclining position shown in dotted lines in Fig. l. It will be understood, however, that bef fore this further swinging movement lof the derrick may be carried out, the pins 26 must be unlocked from the plates 25, which is done 4by removing the yokes 21 so that the pins'26 may swing upward through an arcuate path. During this downward swinging movement of the derrick-that is to say, the movement of the derrick which results in a rightward movement of its center of gravity from the position indicated at'` G"-the vertical load of the'derrick is carried by the lower ends I9 of the front legs I8.

Erection of the derrick at a suitable location is carried on as follows. The base II, Fig. 1, is supported by suitable foundation such as indicated at |z and the parte la, I4, and z'l'are mountedthat the pivot point on which the derrick swings Y is'ftransferred` from the pins 33 to the pins 26. Thederrick is .then pulled leftward so as to swing the center of gravity from the position G'. to substantially the position-#G andthe supporting pins 36'` are"placed.as.shown,in Fig. 4, and are, --thenlocked in position bythe yokes 40. Upon release of strain fromthe lifting lines 22' and 23,

the load of the derricklwill be allowed to settle upon the four leg supports I1 and 20. The placing of the yokes -21 so asto extend over the ends -of the pins 26 will lock the lower ends I6 of they rear derrick legs I5 to the rear supports l1.

I n the practice ofthe invention there is anl`4 adjustment of the supporting means for the front legs I 6 of the derrick which' will permit the weight of the derrick to" act to swing the derrick forward forwardly into reclining position.

In Fig. 5 I show a derrick front leg- I8' 'which'is locked to afront leg support-'.20' consisting of a A pair of plates 29' having vertical channels 3|' .t0

receive the ends of -a pin 3l' which extend through the lower end of the 'leg I8', making it possible for the front leg I8' to move downward when -a supporting pin 36' is removed from the position in which it is shown. The lower end of each front leg I8' constitutes a member which is in continuous overlapping relation with the front leg through the supports 2li'y to the base or foundaa tion. Therear legsupport. l1', shown in Fig. 6, vcomprises a parof vertical plates 25' between which a permanent pin 28 extends so that it may be engaged -by the notched lower end of a rear "leg l5', so that the derrick will be thereby sup-` ported. lf The leg l5' is held against upward movement by a locking pin P which is passed through aligned openlngsm the putes z5' and in the1eg member I5'. When it is desired to tilt the derrick forwardly, as described in relation to Fig. l, the locking pin P is removed ,so that the leg I5' may swing upward from engagement with the supporting pin 2B".

I claim as my invention:

1. A portable derrick assembly comprising a supporting base, a-d'errick which is tiltable on the supporting base between erect and'reclining lpositions, rear legs for said derrick havingtheir lower ends positioned rearwardly of the center of gravity of theerect derrick and front legs for said derrick having their lower ends positioned forwardly of such center of gravity, a rear mounting means for pivotally mounting the lower ends of each of said rear legs on said base and for permitting separation of said rear legs from said base, and front mounting means for mounting the lower ends of each of said front legs on said base, the front mounting means for each front leg including anupwardly extending member on said base having vertically spaced first and second load supportingfshoulders thereon, a projection on each front leg for engaging said first shoulder for supporting said front legs while said derrick is in erect position, said projection being removable from'engagement with said rst shoulder to permit initial forward tilting of said derrick about said rear mounting means, and a second projection on eachv front leg positioned above said second shoulder while said derrick is in erect position but engagingsaid second shoulder after said initilting of said derrick is about said second shoulder as a center. 4

2. A portable derrick assembly comprising a supporting base, a den'ick-which is tiltable on the supporting base between erect and reclining positions, rear legs for said derrick having their lower ends positioned rearwardly of the center of gravity of the er'ect derrick and front legs for said tial forward tilting has occurred to. thereafter 4support said front leg whereby further forward in erect position, said projection being re-mrzlvablel from engagement with said upper shoulder to permit initial forward`tilting of said derrick about said rear mounting means, and a second projection on each front leg positioned above said lower supporting shoulder while said derrick is in erect position but engaging said lower shoulder after said initial forward tilting has occurred to thereafter support said front leg whereby further forward tilting of said derrick is about said lower shoulder as a center. v

3. A portable derrick assembly comprising a supporting base, a derrick which is tiltable on the supporting base between erect and reclining positions, rear legs for said derrick having their lower ends positioned rearwardly `of the center of gravity ot the erect derrick and front legs for said derrick having their lower ends positioned forwardly of such center of gravity, a rear mounting means for pivotally mounting the lower ends of each of -said rear legs on said base and for'permitting separation of said rear legs from said base, and front mounting means for mounting the lower ends of each of said front legs on said base, the

front mountingmeans for each front-leg including an upwardly extending member on said base having vertically spaced upper and lower load supporting shoulders thereon, a pin projecting from each front leg in la position to engage said upper shoulder to support said front legs while the derrick is in erect position, said pin being removable to permit initial forward tilting of said -derrick about said rear mounting means, and a second pin projecting from each front leg. in .a

position' abovey said lower shoulder while said derrick is in erect position but engagingsaid lower shoulder after said initial forward tilting has occurred to thereafter support said front legs whereby further forward tilting of said derrick is about said lower shoulder as a center.

4. A portable derrick assembly comprising a supporting base, a derriclr which is tiltable on the supporting base between erect and reclining posi-` tions, rear legs for said derrick having their lower ends positioned rearwardly of the center of gravity of the verect derrick and tron-t legs for said derrick having their lower ends positioned forwardly of such center of gravity, a rear mounting means for pivotally mounting the lower ends of each of said rear legs on said base and for permitting separation of said rear legs from said lbase', and front mounting means for mountingV lthe lower ends of-each of said front legs on said base. the front mounting means for each front leg including a member on the base and a member on the'front leg in continuous overlapping relation, one of said members having iirst-and 'second shoulders thereon in vertically spaced reladerrick having their lower ends positioned for-v wardly of such center of gravity, a Irear mounting means for pivotally mounting the lower ends of each of said rear legs on said base and for permitting separation of said rear legs from said base, and front mounting .means for mounting the lower ends of each ofV said front legs on said base. the front mounting means for each front for-supporting said front legs while said derrick is tion and the other of said members having aflrstprojection for engagement with said rsty shoulder for supporting the front leg while the derrick is in erect position, said. first projectionA being `disengageable from said first shoulder to permitv initial forward tilting movement oi'said derrick about said rear mounting means, and a second projection on said other member for engaging said second shoulder after said initial forward tilting movementhas occurred to thereafter support said front leg whereby further forward tilt- 'ing of vsaid derrick is aboutlsaid second shoulder i as a center.`

5. A portable derrick assembly comprising a supporting base,'a derrick which is tiltable on the supporting base between erect and reclining positions, rear legs for said derrick having their lower ends positioned rearwardlv'of the center of gravity of the erect 4derricl: and front legs for i ysaid derrick having their lower ends positioned forwardly of such center of gravity, a rear mount- 1 ying means -for pivotally mounting the lower ends n `of each of said rear legson said 'pase and -for permitting separation of said rear legs from said f base, and front mounting means for mounting 1 the lower ends of each of said front legs on said base, the front mountingl means for each front leg including a member on the base and a member tion, one of said members having iir'st and second 1 shoulders thereon in vertically spaced relation and the other.- of said members having a first i projection for engagement with said iirst shoulder l on the front leg in continuous overlapping rela.-

about said rear mounting means, a second projection on said other member for engaging said second shoulder after said initial forward tilting movement has occurred to thereafter support said front leg whereby further forward tilting of said derrick is about said second shoulder as a center, and means of interengagement operative between said members for limiting the extent of upward movement of the front leg whereby rearward toppling of the derrick about said rear mounting means is prevented.

HOWARD D. II-IILBORN. 

